It is the pension plan's first commitment to the management firm, which was started last year by former executives of KKR.

Separately, Mr. Harbin said the plan returned 13.4% for the year ended Dec. 31, surpassing its policy benchmark by 60 basis points.

International equity was the top performer at 17.3%. It was followed by domestic equity, 16.6%; high-yield bonds, 15.6%; real estate, 12.2%; alternatives, 8.8%; fixed income, 6.9%; and timber, 3.1%. Alternatives is primarily made up of private equity, Mr. Harbin said in a telephone interview.